Colorado law makes CC inside a car equivalant to OC outside a car.
A person who may lawfully possess a handgun may carry a handgun under the following circumstances without obtaining a [CC]permit and the handgun shall not be considered concealed:
(I) The handgun is in the possession of a person who is in a private automobile or in some other private means of conveyance and who carries the handgun for a legal use, including self-defense.
There are no restrictions onOC in a national forest, although there are some restrictions on target shooting, which tend to vary from place to place.
In general terms, don't carry into any government building, and you'll be fine.